def h_damped(n,s,t,u,v):
     if n < left_damp:
         e = (left_damp - n) * 1.0/left_damp
         return (1 - e*1.j) * hu.h_nn(s,t,u,v)
     elif sim.N - n < right_damp:
         e = (right_damp - (sim.N - n)) * 1.0/right_damp
         return (1 - e*1.j) * hu.h_nn(s,t,u,v)
     else:
         return hu.h_nn(s,t,u,v)
def h_nn(n,s,t,u,v):
    if n == imp_pos + sim.grown_left - sim.shrunk_left:
        return (1 + lam) * hu.h_nn(s,t,u,v)
    else:
        return hu.h_nn(s,t,u,v)